Guess What We Learned in School Today is a farcical comedy about sex education in the United States. Dr. Whitehorn, the female leader of The Institute for Interpersonal Relations, tries to persuade the parents of a small, conservative, suburban community that the sex drive is a normal human desire which children should know about and understand.

She wants to institute a program of sex education in the local high school.

The entire community gathers forces to protest against her plan. Lance Battle, who leads the opposition, is an impotent alcoholic, and his chief supporter is Roger Manley, a homosexual detective who is certain that sex education is a plot to undermine the morale of American youth. Their wives, however, are fascinated by Dr. Whitehorn's plans, and, as they spend their afternoons together, smoking marijuana, they plot to help their children by giving them first-hand sexual experience. In a riotous series of events, the investigators discover that they and their wives actually have more problems with drugs, sex, and alcohol than their children. In the end, they all join Dr. Whitehorn's institute.